Enhancement: Use S3 for active storage (#398)

config/environments/production.rb

@@ -36,7 +36,7 @@ Rails.application.configure do
   # config.action_dispatch.x_sendfile_header = 'X-Accel-Redirect' # for NGINX
 
   # Store uploaded files on the local file system (see config/storage.yml for options).
-  config.active_storage.service = :local
+  config.active_storage.service = ENV.fetch('ACTIVE_STORAGE_SERVICE', 'local').to_sym
 
   # Force all access to the app over SSL, use Strict-Transport-Security, and use secure cookies.
   # config.force_ssl = true